Method and apparatus for forming hollow metallic structures



July 12, 1932. J. L. ADAMS. JR

METHOD AND APPARATUS FDR FORMING HOLLOW METALLIC STRUCTURES 5 Sheets-Sheet 1 Filed Jan. 3, 1928 I I mmmkoi July 12, 1932. J. L. ADAMS, JR 1,856,609

METHOD AND APPARATUS FOR FORMING HOLLOW METALLIC STRUCTURES Filed Jan. s, 1928 a Sheets-Sheet 2 July 12, 1932.

J. L. ADAMS, JR

METHOD AND APPARATUS FOR FORMING HOLLOW METALLIC STRUCTURES Filed Jan. 5, 1928 3 Sheets-Sheet 3 m m W ATTORNEY.

Patented July 12, 1932 5 UNITED STATES PATENT or E iTAliIES LUCIAN ADAMS, {IR- F EAST CHICAGO, INDIANA, ASSIGNOROF NTI\T ;li1 'EETB'PJ.I-IS.

"OF EAST CHICAGO, INDIANA, A CORPORATION OF onAv-nn CORPORATION, ILLINOIS IJIETHOD AND APPARATUS FOR FORMING HOLLOW METALLIC STRUCTURES 'Thepresent invention relates broadly to the art of bending and.shaping.materials, and more particularly to the bending and shaping of metal sections in such manner that a plurality of suchsections may be assembled to form a tubular structure.

'One of the objects of the present invention is to provide a method and apparatus effective for rapidly and accurately forming up 0' plate sections in. such manner as to permit the assembly of successive sections byl'an interlocking operation, the invention .not only insuring greater accuracy, but. also giving greater rigidity in the formed articles with t c same eneralinechanical a earance and a: 7

enablingthe same to be turned outat a lower total cost than has heretofore been customary. with the usualmethods of construction.

" rided a method .andmeans for accurately, eX-

peditiously, and inexpensively assembling a hollow.metal structure,:of almost any desired total length, from ring sections, which sections-are in turn formedup individually and aa'rapidly from plate stockfof such dimensions as will give thefllowest materials cost.

In the accompanylng drawings .1; have shown for purposesof illustration only one preferred apparatusadapted to facilitate the;

formationand fabrication of ring sections of the character .referred to according to the method of my .inventlon.

In the drawings, Figure 1 is a longitudinal ..vertical sectional view through one form of machine in accordance withthe present in- Figure 5 is a perspective view of a detail.

lnaccordance with the present invention theremay be provided an apparatus including a somewhat expansible hollow drum or C-shaped ring 1, in which theseam has purposely been left open to permit a limited exlVit-h the aboveobject in view, there is pro- Application filed January 3, 1928. Serial No. 244,335.

pansion and retraction of the drum as may be required. This drum, as clearly indicated in Figure 1, has a tapered and threaded interior bore with which cooperates a bushing 2 having its outer periphery similarly tapered and threaded in such manner thatit may be screwed into or unscrewed from the drum 1. This bushing has a substan v tially cylindrical interior bore ,provided with a. thread having thesame pitch-and extending in the same direction as the thread on its outer surface, and cooperating withthe threaded exterior of an inner spider 0r wheel 3. v p

The spider 3 is in turn carried by a longitudinally extending shaft 4 insuch mannor that it may be keyed thereto for rotation simultaneously with the shaft, or re leased therefrom to permit rotation of the shaft with the spider in .predetermined ifixed position. 1

For effecting engagement and disengagement between the shaft-andthe spider- 3' there is provided a clutch oof the key type, adapted to. be cont-rolled at will 'by the machine operator through means of a double throw shifting mechanism, orequivalent de-- vice, 6, indicatedat the left hand end ofthe;

machine in Figurel. The key clutch 5 has a pivotal mounting 7 within'the shaft 4 and comprises three fingers or arms projecting- 111 a generally rad al d1rect1onfrom the p1v-.

otal mounting.

In the position illustrated in Figure 1 of the drawings, the fin er 8 of the key clutch is .in engagement with the spider 3, thereby insuring concomitant rotation of the shaft and the spider. By rotation of the hand wheel 6, the rod 9 may be moved to the left, thereby swinging the key clutch 5 in a counmounting, and effecting disengagement between the finger 8 and therspider. Continued.

ger 10, one of the springs 12 will further ,ter-clockwise direction about, its pivotal swing the key clutch in a counter-clockwise direction to effect engagement between the finger 10 and such key-way, whereby the gear 11 will be keyed to the shaft 4 for rotation therewith.

The gear 11 inturn meshes with a gear 13 carried by a shaft 14 extending transversely of the spider 3, and provided on its opposite end with a pinion 15 in mesh with a gear 16 on a second shaft 17 also mounted in the spider, and carrying on its opposite end an elongated pinion 18.

The teeth of the pinion 18 mesh wit-h the internal gear teeth 19 on the inner periphery of the bushing 2, the bushing in this respect constituting a ring gear. Thus when it is desired to rotate the bushing 2, the hand wheel 6 is turned to move the rod 9 to the left, as viewed in'Figure 1, this motion causing the key clutch to engage the gear 11 and in turn, through the various gears referred to, the bushing itself.

Upon rotation of the hand wheel 6 in the opposite direction, the key clutch 5 is turned in a clockwise direction, asviewed in Figure 1, thus bringing it into such a position that whena key-way in the spider 3 comes into alinement therewith, the other of springs 12 will produce the desired engagement between the key clutch and the spider.

The shaft 4 is carried in an elongated bearing 19 carried by a base 20 along which both the bearing and the shaft can be slid axially. Such movement of the parts is produced bya lead screw 21, which in turn "may be driven by a motor 22 through a suitable gear train 23 controlled by a gear shift 24. With this gear shift in its dotted line position, as indicated in Figure 1, the motor is operatively connected to the lead screw through the gear train. With the gear shift in its full line position, the motor is operatively connected through a second gear train 25 with the shaft 4 for rotating the same; The construction of the parts is pref- "erably such that different gear ratios are provided for driving the shaft 4 at diflerent speeds, and the motor itself is also preferably of variable speed type for giving a furilfiel range of speeds to the operation of the s a t.

The operative connection between the hearing 19 and the lead screw is provided by a projection 26 internally threaded to receive the lead screw, so that upon rotation of this screw the bearing will be slid axially in one direction or the other.

The purposeof sliding the bearing 19 together with the shaft 4 is for enabling the outer drum 1 indirectly carried by the shaft Lo be withdrawn axially from the rest of the apparatus when necessary for the proper operation thereof. Thls other apparatus comprises a pairof clamps 27, as shown in Figure '1 2, having a pivotal mounting 28 adjacent their lower ends. Carried by one of the clamps is a motor bracket 29 on which is mounted a motor 30, the armature shaft of which drives a worm or spiral 31 meshing with a worm wheel or spiral 32. The gear 32 in turn connected to a crank arm 37 driven by the gear 32. Consequently, by operation of the motor 30, it is possible to rotate the gear 32 and thus move the crank 37. Movement of this crank through substantially 180 in a counter-clockwise direction, as viewed in Figure 2, will loosen the clamps from the position shown in this figure, while rotation through a similar distance in the opposite direction will bring them into the position illustrated.

The clamps 27 adjacent their upper ends carry heavy electromagnets 38, while one or more similar sets 39 are provided adjacent their lower ends closely adjacent the pivotal mounting 28. All of these electromagnets are preferably so interconnected that they may be excited at will by means of a double throw switch 40 and the customary direct current supply lines 41, as indicated in Figure 1.

The clamps 27 are provided on their inner surfaces adjacent their opposite sides with any desired number of grooves 42, as indicated in Figure 1.; Mounted for cooperation with a selected pair of these grooves are sets of spinning rollers 43, these sets of rollers being in'spaced relationship axially of the shaft rollers 49 cooperate with a groove 51 in a nut 52, while the rollers 50 co-operate' with a similar groove 53 in a nut 54. These nuts are both internally threaded for cooperation with the respective threaded portions provided on the shaft 4 on opposite sides of the spider 3.

V Projecting laterally from the spider 3 is a rotation stop 55 adapted to control the operation of the nut 52. The rotation of the nut 54 may conveniently be controlled by a suitable brake 56 or similarly functioning device operated by an eccentric clamp, bolt, or other control mechanism 57 at the will of the operthe shaft 4 rotates within it. 1 rAlthough-asingle spinning rollerrmi'ght be used acljaicentzeach side 0f the apparatus there are preierablyiza plurality r spaced equidistantly saronnd the "axis .of the I'Sl'lfilf-t "4 in such manner as to approximately balanee the radial thrusts which-would otherwise the encountered and which the'shaft would have-to Withstand if onlyesinglerollers were utilized. Sincenach of theznuts:52sand 54'is:adaptedito simultaneously control a pluralityaofvsuch rollers, increasing the :numher'athereof does not involve any increasedqdifiiculties.

Figure 1 of the drawings Iihaveinidieateda plate "5.8 inoperative position within the machine with its opposite edges coverlyingccertain ofthe grooves 42 in position-tobe engaged :by the rollers The groove or groovesAQadjacent one side-'otthe clamps 27' are just enough different :as :to dimensions from the grooves 42 adjacent the opposite sides of the-fol amps :as to produce the :formainn iinzopposite'edges :of a plate'of ribs of such :character rthat if the rib :formedin one could he put inside :of that formed "in the other, 'the two would be ".fOUIld to :fit .asnccurately and completely as the difiicultiestof nachineficonstruction -will readily permit. lt wi'llreadily be apparent itO thoseskilled in the :art that the grooves may "be arranged in any desired imanne-r and so spaced. that'ditferent combinations can be utilized with dates of different 'WliCllBhS,*fiI1tl I that .the' supporting disks 47 and '48 can *be so positioned as'to conperate with theidesired :'arrangement of rooves; 1

l his adjustment of the "disks 47 can be East-ed by removing the keys which tasten these disks in 'position' 'on the sha ft,;rotating said disks on the "threaded portion of shaft .on whichsuch-disks run like nuts,-1and then re-keyin g when the disks have reached he proper-position ariially alongthe shaft, to

align wit-lithe required grooves.

grooves '59 adapted to provide clearance room for'one or more grips 60, as indicated in Figure-2. These gripsare utilized for engaging the-ien'd'of a plate "58 for drawing it around the drum 1 as the drum is rotated by the motor '22. These grips are conveniently lnountedron aisihaft 61 located ilustiwmhlin fihe dotted'outline such a head, this again being outer peripheryof the drum so that they can be released and allowed to drop in radially to clear a plate 58 after they "have performed their normal function. Anytype 'of'meo'hanism which will accomplis'h this release and disappearance of the grips, underthe control of the operator, can be utilized at will, the construction illustrated "comprising ecc'entrically operated grips 7 adapted to close when the control 'le erbQ is in position therein.

moved inone direction, and releaseand-drop inwardly when it is moved in the opposite direction. Anyother preferred arrangement of-grips -might-,fhowever, be utilized at will.

land 5, the machine may also be'provided withcontrol means'63 which comprising a Asindicated more particularly in Figures 79 hand operate'dca nsha'ft isa dapted to throw I abolt in a generall-y radial direction in such mann'er as to engage with a suitable opening in'the drain-1' to hold it-stationaryat such times as required whenthere is no plate 58 'l/Vhen such a plate is in position, the drum can-still be readily held from rotation'when required "by 2 energizing the various electromagnets which can be so arranged and'of such construction that the drum is firmly heldcven-through the full thickness of the plate '58. Even after thedrum has been "re leased, its own-great inertia can be utilized to prevent its material rotation until the bushing 2 has been driven backwardly to the extent requiredto properly collapse the drum. In the'preferred embodimentof the inven-V tion,the final seam between the two more or less parallel and straightedges of the plate 58,'after the latter has been formed up, will be in proper operative relation to welding means 6 4L'to permit such edges to be rapidly and "accurately welded or otherwise joined together; i i

In order to facilitate a better understandingjof the invention, there is illustrated in Figure?) of the drawings one form of article adapted to be made in accordance with the present invention. In this figur'e'there arcindicated sections S and S formed from plates such-as the'plate 58 adapted to be assembled witha third section S under process of formation from another similar plate. Similarly, for purposes of description, and not as part ofthe invention itself, there is indicatedv a'dished andflanged ta'nk'end 65 cooperating I with the section S anda second similar head 66 similar tothe head 65 except that its enter The clamps 27 are also provided at suitablepositions in their inner faces with other flange will be slightly difierent in radius, making it suitable for cooperationwith the lett'hand rib, as indicated on the section S The heads 65 and 66 are only to be used specified, and in Figure vl I have indicated in for supplementary purposes and in order to vindicate-the adaptability of the machine in 'meetingtherequirements of the various types of assembly; 1"

the drawings there is indi- 'cated in section the type of joint produced :"for exainple between the section S and the see- In Figure of tioifs. It will-be understood that this joint is similar to and representative of the variwhenand it called for by the specifications of -the particular structure being fabricated Occasionally substantially flat tank ends are ous other joints between the parts'of any complete article. v

In the normal use of an apparatus as herein described, there will be provided at one 5 side of the machine, at proper height for ready feeding, a plurality of plates similar to the plate 58, each properly trimmed and ready for insertion into the machine.

Assuming that a preceding assembly process has involved the operation of the lead screw 21 for withdrawing the drum 1, spider 3, shaft 4 and bearing 19 to a point outside of the enclosing limits of the clamps'27, the first step in the new assembly operation will be the reversal of the motor 22 in order to restore the drum 1 and its associated parts to the position illustrated in Figure 1 of the drawings. Thereafter, the bolt operated by the control lever 63 is thrown to engage the proper opening, depression or slot in the drum 1 to thus hold the drum. against rotation.

The gear shift 24 is then thrown to its full line position as indicated in Figure 1 and the gearing 25 set for low speed operation. The key clutch 5 being in position to engage the gear 11, the motor 22 is again started without further change in its direction of rotation and is thus effective for rotating the bushing 2 and to effect movement thereof to the right, as viewed in Figure 1, thus drawing the bushing into the drum and expanding the latter to its outermost position as determined in any desired manner, after which the motor is deenergized.

The control 63 is now thrown over to its release position to release :the drum 1 and lie below the surface of the clamp 27 through which it projects. A new plate is then passed from the supply and the grips 60, shown in Figure 2, in a position in substantially the same horizontal plane with the axis of the shaft 4, but which are in reality locatedat this time closely adjacent the point of entry of the new plate, are operated to cause gripping engagement with the leading end of such plate. Thereafter, the hand wheel 6 is operated to disengage the key clutch 5 from the;

gear 11 and bring it into engagement with "Ithe spider 3, and the motor 22 is once more started at its lowest, or at a relatively slow speed. The clamps 27 having been left open after the completion of the preceding assembly operation, the new plate is drawn into ;?oosition around the drum 1 until its endsare brought into closely adjacent relationship, after which the motor 22 is deenergized and approximation of a truly circular shape under the tremendous pressure exertedby the clamps.

The clamps having been brought to this position, the motor 30 is deenergized in any desired manner, either manually or by a suitably arranged limit switch, as well understood in the art.

Ifdesired, the electromagnets 39 may be energized prior to the release of the grips 60 by throwing the switch 40 to the proper position, thereby obviating any possibility of slippage of the plate from its previously determined position during the bringing together of the clamps.

The clamps now being in the position illustrated in Figure 2, and the clutch 5 having been disengaged, the control mechanism 57 is operated to apply the brake 56, it being assumed thatthe rotation of the control means for the inner nut 52 has been previ- ,ously so adjusted that itneed not be disturbed. I V

The gearing 25 may now be set at one of its higherspeed positions and the motor 22 again energized, thus rotating the shaft 4 and forcing the nuts 52 and 54 to travel along threaded portions of the shaft 4, carrying with them the respective rolls 49 and 50. v This in turn efiects movement of the levers 44 and 45 in such manner as to swing the spinning rollers 43 into their respective grooves 42 in the clamps 27. This operation may be continued until the nuts 52 and 54 are brought into engagement with suitable limit stops or into engagement with the sides of the disks 47 and 48, thus stopping their travel and causing the brakes 56 or other appropriate control mechanisms for the nuts to slip until such time as the operator judges that the spinning process is completed. Thereupon he reverses the driving means 22, preferably setting it at still a higher speed for this purpose, and maintainssuch speed until the nuts 52 and 54 have been caused to retrace their paths to their original positions, approximately as shown in Figure 1. If desired, a limit stop or limit indicator '67 may be provided for cooperation with the I, nut 54, although such a device is not essential. VVhenthe nuts have reached their proper positions, the motor 22 is again deenergized. a a At this time the further procedure de-r pends upon whether or not any left-hand end head 66 is to be incorporated in the completed assembly of parts. If such a head is diameter of the drum 1 sufiiciently to enable itto. clear the inner face of the formed ring, but it need notbe removed from the position illustrated in Figure 1 in order to permit the final removal of the completed ringsectionand its incorporated parts.

In order to completely describe the operation of the machine, there will first be assumed a condition of operation in which a head of the character referred to is to be incorporated. In such case, when the nuts 52 and 54 havereached the left hand limits of their travel ,-as viewed in- Figure 1, the motor 22 iszshut' oil? and the shaft 4 allowed to: slow down until it isturning over slowly enough to" permit the clutch 5 or the equivalent device provided for that purpose to be operated through the medium of the. hand wheel 6 tobring it into such position as to engagethegear 11. At this time, the motor gear train 25, having again been set to a low speed position, the electromagnets 38 and 39' are energized by proper movementofthe switch: 40, and the motor 22 again brought intooperatiomwith the clutch 5 in such position astocngagethe gear 11- in order to'back out" the bushing 2 to an extent suflicient to permit contraction of the drum to a small enough diameter to permit its ready sidewise removal' from the formed-up plate. air Thisasidewiseremoval is accomplished by deenergizing the motor 22until such time as=the gear shift 11 can be moved toits dotted: line position and the gear train 25 again changedto its high speed point. At such fl time the motor 22 isagain. energized, preferably at its highest speed of rotation, so that theentire rotor element, including thedrum 1 and itsassociated parts; is rapidly moved toa the left, asviewed in Figure 1, at'which {ii -time the motor is again shut down.

The electromagnets 38 and 39-are maintained energized and the driving means operated to open the clamps 27 and withv them, due'to the action ofthe electromagnets,

fl the now formed plate ring, ready to permit the'entry of a previously formed ring section or the entry of a suitablyshaped right or left hand head, or any other-part as re p quired' by the specification.

After the proper: positioning of such part or' partsin their=respectivegrooves provided,

the motor- 30 is energized to once more draw the: clamps 27 into operative position to close the lastformedplate ring about the part or part's previously positioned in'the desired grooves With thecl'amps'in closed position, the motor 30 is deenergized, thus leavingthecomponentparts of the final tubular structure, insofar as as they have been assembledby' this operation, firmly locked to-" gether'. In this-position the axial seam between the two approximately parallel ends of thelast formedplate ring may be closed" permanently by means: of the arc welder or welders-64'; or by any: other equivalent or dc a desired species of dovetailingpreviously' incorporated in the ends'of the plate, andthe final sealing up or completion of the seam carried out as a subsequent step after the parts have left the machine.

' With such welding or mechanical closure of the axial scam in the last formed plate ring, the process of assembly by a machine 1n accordance with the present invention ceases, it being now only necessary to; again energize the motor 30 to open the clamps'27 and thus permit theremoval of the'for'med up and assembled parts.

If the new ring section just formed 'constitutes an intermediate, and not anen d sec tion ofthe total tubular structure'beinggfab ricated, upon its withdrawal to one side of the machine it may correspond for example to thesection S ofFigure3, where it is ready' for theincorporation therewith of the next ring section S to be subsequently formed up. In this manner, the parts are formed andassembled until a complete tubular structure is produced, of any desired number of sections or length, which'may or may not-be provided with one or bothends headed, at

the users option. r a

The carrying out of the processherein de scribed leads to several important advantages besides those of rapid production and relatively low cost. Thus, the ribs pushed out or formed around the circular 'edges of v the formed up ring plate are precisely and accurately positioned and placed, thereby" leadlng to greater accuracy in the final structure regardless ofwhether the original raw plate was aperfect rectangleior more orless trapezoidal in its contour, and re ardless of whether it was wavy, of non-stan ard width, or positioned slightly askew in the machine. These constitute important manufacturing advantages not only because of the production ofmo're accurate articles regardless of errors in anypreceding operationsybut be cause of the fact that they obviate thenecessity of that. degree of accuracy in preceding operationswith respect to trimming, shear-" ing, and feeding of the parts as has: beforebeen necessary. V 1 r A structure produced 111 accordance with the present invention will be strong, and" firmly held together mechanically without furtherprocessing; If, however, it is to be made liquid or gas tight, all of the seams maybe hot-dip brazed, galvanized, electricfare or gas Welded, or otherwise sealed in a subsequent operation, independent jof 'the steps of assembly-before referred to.

The projecting circular ribs as formed 7 being machine constructedfin accordance assembly with said plate with the present invention, not'only serve as a logical, convenient and efiective mechanical means for joining successive ring sections, but at the same time give that projection of the joint outwardly from the general cylindrical surface of the article necessary to permit ready entry into the molten brazing, galvanizing, or other bath, whereby a substantial inexpensive and expeditious method of sealing is obtained.

WhileI have herein illustrated and described a preferred embodiment of the present invention, it will be understood that changesin the construction, arrangement and operation of the parts may be made without departing either from the spirit of my invention or the scope of my broader claims.

It will also be apparent that changes in the contour of the various sections may be made at will. The expression tubular and similar terms used throughout the specification and claims are thus definitive of a wide variety of difierent shapes, it being only necessary within suchterminolo'gy that the opposite end portions of a plate shall be brought into adjacent relationship.

. 1. In a machine of the character described, means for bending a plate into the desired form, electro-magnetic means for holding the plate in formed position, means for forming a flanged projection near one edge of said plate, and means for moving said electrow-magne-tlc means to open the formed plate and facilitate the assembly therewith of a second plate. l V

2. In amachine of the character described, means for bending a plate into the desired form withthe end portions thereof in adj acent, relationship, holding means for said plate, means for forming a flanged projection near one edge of said plate, and means for moving said holding means to separate the end portions of the plate and permit the of a previously formed plate section. I v

3. In a machine of the character described, means forbendinga plate into the desired form with the end portions thereof in adja- V centrelationship, holding means for said plate',. means for forming, afianged projection near one edge of said plate, and neans for moving said holding means to, separate the end portions of the plate and permit the 4 V assembly with said plate of a previously formed plate section, said holding means comprising an electro-magnet.

4. In a machine of the character described, means for forming a plate to bring the end portions thereof into adjacent relationship,

means for deflecting an edge portion of said.

late and means 0 erable at will for oneu- 7 A ing or closing the formed plate to effect a separation of the end portions thereof.

5 In a machine of the character described,

means for forming a plate to bring the end portions thereof into adjacent relationship, means for deflecting an edge portion of said plate, means operable at will for opening or, closing the formed plate toeifect a separa portions thereof into adjacent relationship,-

means for shaping the opposite edges of said plate to provide interlocking projections thereon, means for separating and bringing together said end portions at will, and means for securing said end portions.

7. In. a machine of the character described,

means for deflecting a plate into the desired form with the end portions thereof in adj acent relationship, means for producing an interlocking element near one edge of said plate, means for expanding the formed plate to permit the association with said interlocking element of an interlocking element on a previously formed plate, means for contracting said plate to interlock said'elements, and

' means for joining the end portions of said plate.

8. In a machine for fabricating metal.

expanding and contracting at willa shaped.

section prior to the joining of the ends there:

of to facilitate the assembly therewith of an other section. I

9. In a machine of the character described,

a drum, means-for fitting a plate around said drum, means for expanding 'or contracting said drum, clamp-ing means extending peripherally of said drum, means for operating said clamping means, and means for moving the drumandclamping means relativelyone to theother in a-direction axially of the,

drum.

ion

10. In a machine of thecharacter de--. SCIlbEd, a drum, means for fitting a plate; around said drum, means for expanding or,

contracting said drum, clamping means eX-ttending peripherally of said drum, means for operating said clamping means, means for moving the drum and clamping means relatively one to the other in a directionaxially" .of the drum, and means cooperating with said drum and clampingvmeans for forming an interlocking elementon a plate in position therebetween.

11. In a machine of the character dQ-i? scribed, a drum, means for fitting awplatev around said drum, means for expanding or; contracting said drum, clamping means ex- I tending peripherally of said drum, means for operating said clamping fmeans, means for moving the drum and clamping means rela-,

tivelyone to the otherin a direction axially 1&5 sections having interlocking elements formed.

thereon, meansfor SHCCQSSlVfibZ-g expanding one of said sections to permit the assembly lindrical metal structures, the steps comprisof the drum, and means cooperating with.

crating parts" of said first section into engaging relationship, and meansfor holding saidsections inLassembled relationship,

structures, means for forming-a. successionof therewith ofa previously formed section and thereafter contracting the expanded section,

andlme'ans. for. securing said. contracted section 1n contracted pos1t1on, -,yvhe reby sald m terl ocking elements unite saidsectionsJ 14; In a machine for assembling tubular metal structures of in definite length, rotat- ;ing meansjfor pullinga plate into substan-;

tially V tubular form, foo-acting exterior and interior means for holding such formed plateili substantially cylindrical shape, means for forming a beadat the v end of thecylinder, means for opening upv andthen closing ina beaded end to :permitinterlocking. assembly with a similarly and previously formed cylinder, and other means for finally securing togetherthe meeting'edges of said-formed plate so as to permanently interlock with said previously formed-:cylinder 15'. 'In machine for assembling interlocked tubular metal structures of indefinite length, means for pulling a plate around a rotatmg drum, exterior clamping means for forcing said plate into a substantially cylindrical shape. roller means for forming interlocking projecting ribs at an end of the cylinder, means for then holding the formed plate and opening it sufficiently to permit interlocking assembly with a substantially similar and previously formed plate, clamping means for efi'ecting such assembly, and means for securing; the meeting edges of the plate solidly together after such assembly.

16. In a method of assembling holloiv cying pulling a plate around a rotating drum, then exteriorly clamping such plate solidly into substantially cylindrical form, rolling and finally securing solidly together the meet ing edges of the lastformed plate. so as to make the interlock permanent.

17. In a. method of assembling hollow cylindrical metal structures, the steps comprisp p; plying; a, metallic liquid tight seal to 13'. In a machine for fabricating metal;

; Lipsection. 1

20. Iniamethodof assembling indefinitely" ing pulling aiplate. around; a. rotating drum then. exterior-1y. clampingsuchplate solidly intosubstantially cylindrical. form, rolling projecting ribs near the ends of the formed.

tially tubularform, rolling a continuous and projecting. hollow interlock rib near one of the" circularedges of the. formed up plate, opening up such ribbed edge. so to permit assembly ofv the newly formed up plate with.

one. previously formed, reclosingr said opened 1 uprrih so as 'to-solidly grip the interlockina rib of'a previously formed plate. and sealing all ioints so as to make afluid tight structure.

19. In a method-of assembling indefinitely long hollow. metallic multi-sectional structures, the steps including pulling. a plate aroun d} a rotating drum. vformin g edge inter-- lock-elements on saidplate; opening up one interlock element to permit the entrance of a (so-acting interlock e'lementon a. previouslyformed similar tubular section inserting such co-acting element, and reclosing theopenedlong'. hollow" metallic multi-sectional structures, the stepsincluding pulling a plate around.- a: rotating drum into tubular. form,

formingedge interlock elements on said plate opening up an edge interlock element 7 of the newly. formed section so as to permitinter-e locking. assembly- With the interlock element. on a previously formed section,.reclosing the newlyinterlock. element-so. as to form a mechanically'firm jointaround the previously 7 formed element, and" permanently connecting adjacent edges of said opened-up section.

a method ofassembling indefinitely long. hollow: metallic multi-sectional struc- -tures,. the steps including pulling a plate around a. rotating drum to-i'orm atube. roll. ing ed'ge interlock, elements inthe formed? plate,openingupat-leastone ofsaidinterloclt element's slightly so as: to" permit. the interlocking:entrancethereinto of a previously formed smaller "interlock element; reclesing the opened-up interlock element tightly over the previously'foimiedgelement, and firmly securing the. axial; edges of said opened-up plate so as-to; for'ina mechanically integral:

structure:

lock-elements a I 1 22. an; apparatus iforass'embling circular hollowimultiasectionali metallick structures; a:

With the 'previouslyformedsinten I v scribed, a rotatable mandrel for progressive- 1y deflecting a metallic plate into substantialformed plate in position, rotating means" ly tubular form, contractible means having grooves for gripping the formed plate on said mandrel, and rotating means cooperating with said grooves to form hollow bead interlocking projections adjacent the ends of said formed plate, said hollow beads being similar in shape but of different dimensions. 24. In a machine of the [character described, a rotating form for progressively deflecting a metallic plate into substantially tubular shape, means forcontracting around said form to hold the plate thereon, said means having circumferential grooves, means cooperating with said grooves for forming parallel hollow interlock ribs near the cir cular edges of the formedplate, said hollow interlock ribs being similar: in shape :but of different dimensions, means for tightly closing an interlock rib on anewly formed plate over a similar rib on a previously formed plate, andmeans for securing ends of the newly formed plate.

25. In a machine for fabricating Inetal' structures, means for bending a' plate into substantially tubular shape, means cooperating with said bending means "for holding a cooperating with said holding means for forming interlock beads of similar shape but dilierent dimensions close to the circular edges of the formed plate, means for slightly opening and reclosing the formed plate to receive in one of its interlockbeads a matching bead in a previously formed similar plate, and means for securing togethenthe. ends of the last formed late.

26. In a machine -0 the character. de-

scribed, a rotatable form for progressively bending a metal plate into substantially tu- *bular shape to bring the end portions thereof into engagement, external and internal means for gripping said formed plate and 27. In a machine bent to cylindrical shape, internal and external means cooperating with said form to produce interlock beads adjacent "the circularedges of the plate, means-for opening up andclosing a-newlyformed hollow beadover together the of the character de scribed, a form for receiving'a metal plate a matching bead on a previously formed plate, and means for securing togetherthe ends of the last formed plate.

28. In a machine of the character de-' scribed, cooperating .internal and external means for producing interlock beads in the circular edges of a plate bent to tubular form, means for opening u the bent plate and reclosing it in interloc 'ng engagement with a previously formed similar plate, means for tightly closing the ends of the lastformed plate and means for securing said ends firmly together.

29. In a machine for fabricating tubular metal structures, means for holding a shaped tubular'plate, means for producing edge interlocking beads in said plate while so held,

means'for opening up a formed plate and con tracting itaround a previously formed plate toefi ect' engagement of the beads on adjacent plates, and means for permanently secrliring together the ends of the last formed p ate.

30. In a method of fabricating tubular metal structures of a definite length, the steps including pulling a plate around a rotatable form to give it substantially cylindrical shape, forming interlocking ribs adjacent the circular edges of the formed plate, opening one of said ribs, inserting a corresponding rib of a previously formed plate, reclosing the opened-up rib, and firmly securing together the ends thereof. y

In Witness whereof, I hereunto subscribe my name.

JAMES. LUCIAN' ADAMS, JR. 

